The present invention relates to a thermal ink-jet recording apparatus having an ink film whose surface has a number of holes for retaining ink, and a thermal head contacting the ink film in a print position for ejecting the ink out of the holes toward a recording sheet. More particularly, the present invention relates to a mechanism for supplying ink to the holes of the film after a printing operation.
A thermal ink-jet recording apparatus of this type is disclosed in U.S. patent application Ser. No. 07/482,097 invented by the same inventor as the present invention. The conventional apparatus has an ink film formed with a number of holes for transporting liquid ink to a thermal head, and an ink reservoir filled with ink to be supplied to the ink film. The ink film is immersed in the liquid ink in the reservoir to be supplied with the ink.
U.S. Pat. No. 4,801,951 teaches a thermal ink-jet recording apparatus having a pair of spools around which an ink film is wound. The ink film is movable in a reciprocating motion over a thermal head which is located between the spools. The ink film is supplied with ink by being pressed against felt members which is impregnated with liquid ink.
A prerequisite of the conventional thermal ink-jet recording apparatuses be that liquid ink is stored in a reservoir and, therefore, the reservoir requires a structure for preventing ink from flowing out of the reservoir and ink paths. As a result, the ink supply mechanism including the reservoir is bulky, causing the entire recording apparatus to be bulky. In addition, the ink supply mechanism is apt to introduce impurities in the liquid ink and thereby deteriorate it since the ink is held and circulated in a liquid state.